<div class="container">
    <nav class="navbar navbar-expand-lg navbar-light ">
    <a class="navbar-brand" href="#">
    <img src="../img/1.jpg" alt="" width="150px" height="50px">
    </a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent"
aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
    </button>

    <div class="collapse navbar-collapse" id="navbarSupportedContent">
    <ul class="navbar-nav mr-auto">
    <li class="nav-item active">
    <a class="nav-link" href="../index.html">主页 <span class="sr-only">(current)</span></a>
</li>
<li class="nav-item">
    <a class="nav-link" href="#">幸运值</a>
    </li>
    <li class="nav-item dropdown">
    <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button"
data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Dropdown
    </a>
    <div class="dropdown-menu" aria-labelledby="navbarDropdown">
    <a class="dropdown-item" href="#">Action</a>
    <a class="dropdown-item" href="#">Another action</a>
<div class="dropdown-divider"></div>
    <a class="dropdown-item" href="#">Something else here</a>
</div>
</li>
<li class="nav-item">
    <a class="nav-link disabled" href="#">Disabled</a>
    </li>
    </ul>
    <form class="form-inline my-2 my-lg-0 ">
    <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
    <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
    </form>
    </div>
    </nav>
    </div>